Iridium (III) complex with heteroatom linking group and organic electroluminescent device using the same

Abstract

A high-efficient phosphorescent iridium (III) complex with a heteroatom linking group and an organic electroluminescent (EL) device using the same. The iridium complex is represented by Formula 1 or Formula 2: The iridium complex of the present invention complex can efficiently emit light ranging from a blue region to a red region in a triplet MLCT state. The iridium (III) complex can be used in formation of an organic layer of an organic EL device. Since the iridium complex of the present invention can be used as a high-efficiency phosphorescent material, the iridium complex of the present invention can produce white light emission when used together with a green-emitting material or a red-emitting material as well as emission at the wavelength range of 400-650 nm.

1. An iridium (III) complex represented by Formula 1: 
       
         
           
           
               
               
           
         
         wherein Q1 is an N-containing aromatic ring, Q2 is an aromatic ring, and Q1 and Q2 form a fused ring; 
         Z is selected from the group consisting of a thiocarbonyl linking group (>C═S), a sulfoxide linking group (>S═O), a sulfonyl linking group (—SO 2 —), and a combination thereof; 
         m 1  is an integer of 0 to 2 and m 2  is 3−m 1 ; and 
         R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are each independently a hydrogen or a substituent. 
       
     
     
       2. The iridium (III) complex of  claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are each independently a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, an ureido group, a phosphoramide group, a hydroxy group, a mercapto group, a halogen atom, a cyano group, a sulfo group, a carboxyl group, a nitro group, a hydroxaminic group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group, a silyl group, and a silyloxy group. 
     
     
       3. The iridium (III) complex of  claim 1 , wherein the fused ring formed by Q1 and Q2 is derived from one selected from the group consisting of indole, azaindole, carbazole, indazole, harmane, benzimidazole, benzotriazole, benzoxazole, benzothiazole, benzoselenadiazole, benzothiadiazole, benzisoxazole, quinoline, benzoquinoline, acridine, isoquinoline, and a derivative thereof. 
     
     
       4. The iridium (III) complex of  claim 1 , wherein the compound of the formula 1 is a compound represented by Formula 3: 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8  are each independently a hydrogen or a substituent, m 1  is an integer of 0 to 2, and m 2  is 3−m 1 . 
       
     
     
       5. The iridium (III) complex of  claim 1 , wherein the iridium (III) complex is selected from the group consisting of compounds represented by the following formulae: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
       6. An organic electroluminescent device, comprising:
 a pair of electrodes; and 
 an organic layer interposed between the pair of electrodes, the organic layer comprising an iridium (III) complex represented by Formula 1: 
 
       
         
           
           
               
               
           
         
         wherein Q1 is an N-containing aromatic ring, Q2 is an aromatic ring, and Q1 and Q2 form a fused ring; 
         Z is selected from the group consisting of a thiocarbonyl linking group (>C═S), a sulfoxide linking group (>S═O), a sulfonyl linking group (—SO 2 —), and a combination thereof; 
         m 1  is an integer of 0 to 2 and m 2  is 3−m 1 ; and 
         R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are each independently a hydrogen or a substituent. 
       
     
     
       7. The organic electroluminescent device of  claim 6 , wherein the organic layer further comprises at least one selected from the group consisting of at least one polymeric host, a mixture of a polymeric host and a small molecular host, a small molecular host, and a non-emission polymeric matrix. 
     
     
       8. The organic electroluminescent device of  claim 6 , wherein the organic layer comprises a light emission layer comprising 1 to 30 parts by weight of the iridium complex, based on 100 parts by weight of the total weight of the light emission layer. 
     
     
       9. The organic electroluminescent device of  claim 6 , wherein the organic layer further comprises a green-emitting material or a red-emitting material. 
     
     
       10. The organic electroluminescent device of  claim 6 , wherein the thickness of the organic layer ranges from 30 to 100 nm. 
     
     
       11. The organic electroluminescent device of  claim 6 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8  are each independently a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, an ureido group, a phosphoramide group, a hydroxy group, a mercapto group, a halogen atom, a cyano group, a sulfo group, a carboxyl group, a nitro group, a hydroxaminic group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group, a silyl group, and a silyloxy group. 
     
     
       12. The organic electroluminescent device of  claim 6 , wherein the fused ring formed by Q1 and Q2 is derived from one selected from the group consisting of indole, azaindole, carbazole, indazole, harmane, benzimidazole, benzotriazole, benzoxazole, benzothiazole, benzoselenadiazole, benzothiadiazole, benzisoxazole, quinoline, benzoquinoline, acridine, isoquinoline, and a derivative thereof. 
     
     
       13. The organic electroluminescent device of  claim 6 , wherein the iridium (III) complex is represented by Formula 3: 
       
         
           
           
               
               
           
         
       
     
     
       14. The organic electroluminescent device of  claim 6 , wherein the iridium (III) complex is selected from the group consisting of compounds represented by the following formulae: